2.25.2010

So why does the filibuster survive? One explanation is that any proposal to change the rules would itself be successfully filibustered. But with the nuclear option available there is -- at least on paper -- a way to defeat the filibuster. As became evident during the 2005 showdown over George W. Bush's judicial nominations, a committed majority could use procedural rulings to do away with the filibuster.

The minority could retaliate by attempting to shut down the Senate through extreme delaying tactics, but doing so would risk a public backlash, as occurred when Republicans were blamed for shutting down the government during their 1995-96 budget showdown with President Bill Clinton. In the end, a majority that sticks together and has the mettle to withstand a public firestorm has the tools to change the Senate's rules of the game.

The real reason the filibuster survives is that it continues to serve the interests of most senators. The nuclear option would require the support of a solid majority, which means getting the votes of several moderates. But some of these senators -- Ben Nelson and Evan Bayh come to mind -- stand to lose if the Senate becomes a strict majority-rule institution, since the Democrats would no longer necessarily need them to form majorities to legislate.

Regardless of ideological positions, senators appreciate the attention and personal power that they can receive by threatening to filibuster. The concessions granted to Joe Lieberman after he threatened to obstruct health care reform sent a strong signal about the power the filibuster can confers on an individual senator. It would be difficult to find 51 senators willing to give up this kind of power.

For the moment, the filibuster seems to have the support of most senators, despite the palpable frustration of liberal Democrats. But as the gap between the parties continues to grow, it may not be long before a Senate majority party includes 51 members who are sufficiently committed to a shared policy agenda to pay the personal power costs involved in imposing majority rule.